Process of treating rayon



y 1933. w. F. RICHTER ET AL 1,907,667

PROCESS OF TREATING RAYON Filed Dec. 31, 1950 3 Sheets-Sheet l a n 9 c 000 a a 0:0 0 cane Ino oun e can one 0000 00090 00000 00000 00000 000000000 c000 6090 0000 000cc 00000 00000 00000 00000 0 o O 0 on e 00WITNESSES J I I INVENTORS J 1164'... .ZQJQCQ 7X3 6 fi xul/zfi g a, 64M4M4, M M

y 1933. w. F. RICHTER ET AL PROCESS OF TREATING RAYON Filed Dec. 51,1950 3 Sheets-Sheet 2 I|llll llulllllllllluu I". al I INVENTORS #441024,4 fizm w w 41W,

was 9253M May 9, 1933.

w. F. RICHTER ET AL PROCESS OF TREATING RAYON Patented May 9, 1933UNITED STATES PATENT OFFICE WILLIAM F. RICHTER, OF APOLLO, AND HAROLD E.MCCRERY, OF PITTSBURGH, PENN- SYLVANIA, ASSIGNORS TO CHEMICAL HOLDINGCORPORATION, OF APOLLO, PENN- SYLVANIA, A CORPORATION OF DELAWAREPROCESS TREATING RAYON Application filed December 31, 1930. Serial No.505,749.

This invention relates to the treatment'of artificial filaments intendedfor textile and the like uses, and particularly to the collection ofviscose rayon and its treatment with washing and other liquids.

It is among the objects of the invention to provide a method ofcollecting and treating such filaments after their precipitation,

which is simple and easily practiced, provides a product of highquality, and which,

' as compared with prior practice, minimizes fraying and mechanicaldestruction of the filaments, effects more uniform. liquid distributionduring treatment and provides a product of higher quality, and afi'ordsmarked economies in treating times and amounts of liquid required. I

A further object is to provide means upon which artificial silk and thelike may be reeled for washing and other treatments, which provides forthe collection and treatment of the material in relatively large units,is simple, sturdy, easily used and which is particularly adapted for usein the practice of the method just referred to.

Other objects will appear from the following description:

The invention may be described in connection with the accompanyingdrawings, I

in which Fig. 1 is an elevation of the preferred embodiment of the drumprovided by the invention; Figs. 2 and 3 enlarged fragmentary sectionsthrough an end portion and the body of the drum, respectively, showingdetails of construction; Fig. 4 an eleyation taken on line IV'IV of Fig.5, showing a treating apparatus embodying the drum shown in- Figs. 1 to3,, for use in the practice of the invention; Figs. 5 and 6 plan andside elevation views respectively of an apparatus comprising a pluralityof treating units; and Fig. 7-an end elevation of a drier unit, taken online VII-VII, Fig. 5.

For brevity of reference the method and apparatus provided by theinvention will be described as applied to the production of viscoserayon. It will be understood, however, that they are applicable equallyto other products, such as'artificial wool, and

' other filaments of this general type.

special type which confei-zaparticular bene-' fits and advantages.Thesecomprise relatively closely spaced perforations of small diameterthrough the shell which terminate in depressions of greater size formedin the surface of the shell. Preferably the de ressions are of cup-likeform, with theper' orations located substantially centrally of the base,or lowest point, of the depressions.

Most suitably these depressions are formed on both surfaces of theshell. In other words, in the preferred embodiment the surfaces of thebody portion of the drum are provided with a plurality of opposedconcavities having their bases connected by a perforation through theshell.

After the rayon has been wound upon it the drum is partly filled withwater or other liquid, which is allowed to flow or seep through theperforations under its gravity head alone, and liquid is added toreplace that which flows outuntil the treatment has been completed. Inprior procedures the treating li uids have been applied under pressure,either by forcing it outwardly through a spool under pressure, or bysuck ing it inwardly into the spool. The pressures used have caused theliquids to contact with considerable force with the rayon, which hasresulted in substantial mechanically destructive effect upon thefilaments. It is well known in the art that considerable breakage orfraying of filaments frequently occurs during liquid treatments.

We have found that particular advantages attend the use of large reelsprovided with perforations of the type referred to. The combination ofthe small diameter perforations and the larger depressions at their 2ends produces a spraying effect of liquid passed through them. In thismanner the mechanical action of the liquid upon the filaments is muchmore gentle than was the case in pressure treatments, and mechanicaldestruction and fraying are minimized or eliminated. The spraying actionfurthermore provides more uniform action and distribution of the liquid.

A further advantage of the method provided by the invention .resultsfrom rotation of the drum during treatment in the same direction inwhich the rayon was wound upon it after precipitation. This results in aliquid flow tangential to the filaments, while the liquid flows awayfrom the filaments in the same direction in which the precipitating bathflowed from it during winding. Such uni-directional flow of all of theli uids to which the products are exposed ten s to provide more uniformaction and more thorough removal of impurities, while accelerating thetreatments. All of these factors combine to give a product of improveduality.

Having re erence now to the drawings, with which the preferredembodiment of the invention may be explained, Figs. 1 to 3 represent thedrum. It comprises a substantially cylindrical hollow body portion 1upon which the rayon is wound. Preferably the surface of the drum isdivided into a number of separated rayon-collecting portions, it beingpreferred to provide one such section for each spinneret. This may bedone in any suitable manner, for example by forming swells 2 in theshell.

The rayon-collecting section of the drum is provided with a plurality ofperforations of the type described hereinabove. They may be formed inthe drum itself, but because such drums are often attacked by theliquids used, the surfaces are preferably covered with a protectivecoating. In such inf stances the better practice is to form the pressedinto the perforations 3, forming dia-.

phragms which'are perforated centrally of their bases, either bydrilling openings of small diameter through the diaphragms, or

by molding the perforations when the coat- .ing material is applied. Inthis manner the substantially plane rayon-collecting surface isinterrupted by a plurality of depressions 16 gauge plate.

5 connected by perforations 6 to similar depressions inside of theshell.

In one operative embodiment of the invention satisfactory results wereobtained with drums 37 inches long, having an outside diameter of 16inches, and formed from The drums were divided into fiverayon-collecting sections by swells formed seven inches apart fromcenter to center. They were then coated with inch of rubber after beingprovided with perforations inch in diameter, spaced inch from center tocenter. In order to prevent treating liquid 'from' escaping at the edgesit is preferred to leave an unperforated see-. tion at each edge of therayon-collecting section, and in the embodiment referred to theperforated sections were 4 inches wide. Generally spherical depressionshaving an outer diameter of inch, and about inch deep were formed in therubber coating, and the diaphragms thus formed were drilled to provideperforations inch in diameter.

Although various forms of drum may be used, it is preferred in thepractice presently to be described to use drums having open ends, thesebeing closed by removable heads for treatment. In this embodiment theends of the shell are provided ,with rings 7 Whose outer diameter isgreater than that of swells 2, and which are provided on their innerfaces with a chamfered portion 8 ada ted tn cooperate with a movablehead to orm a liquid tight seal- In the use of this drum the practice ofthe invention rayon from a precipitating bath is wound upon it whilebeing rotated between a pair of adjustable heads which cooperate withrings 8. At the end of the, winding operation treating-liquid, such aswater, is run into the drum to fill it to an appropriate height, andwhile rotating the drum in the same direction the liquid is permitted toflow outwardly through the perforations under the pressure due to itsgravity head. This maybe accomplished in a variety7of ways, one of whichis shown in Figs. 4 to Having reference to Fig. 4, the unit comprises aframework indicated by the numeral 10 which supports a pair of opposedrotatably mounted heads 11 and 12 having inner faces 13 chamfered toengage chamfer 8 on rings 7. Head 11 is movable axially of the drum, anysuitable means,- such as a hand wheel and screw mechanism, not

Treating liquid is introduced into the drum through a hollow trunni'on9which serves to support head 12 also. Mounted below the drum is a tank14 having an outlet conduit 15 to a pump 16 which passes liquid drawnfrom tank 14 through a pipe 17 to hollow trunnion 9, and thence to theinterior of the drum.

The drum having been engaged by heads 11 and 12, rayon is wound upon it,suitable means being provided to form a proper lay of the thread. Whensuflicient thread has been wound, water is introduced through trunnion9, or pump 16 is started in order to pass an appropriate treating hquldinto the drum. The height to which the drum is filled with liquid willdepend in part upon the size of perforations in the drum, and upon theparticular gravity head which it is desired shall exert its efie t inthe washing treatment. In general, it is preferred to use a liquidheight equal to about 75 per cent of the diameter of the drum, so thatin washing with water using the embodiment described above the drum willcontain about 200 pounds of water.

No external pressure is applied to the liquid, which flows out throughthe perforations under its own head. Since the drum is rotated whilecontaining the liquid, the major portion of the liquid flowstangentially of the rayon, and falls downwardly into tank 14, from whichit may be menculated to the drum. The direction of flow of liquid isindicated by arrows in Fig. 4.

Most artificial filaments of the general type herein contemplatedrequire a series of treatments, such as washing with water afterprecipitation, followed by various chemical and washing treatments forthe purpose of preparing the filaments for their ultimate use. In suchinstances the treatments are applied without removing the rayon from thedrum upon which it was initially wound. A single unit like that justdescribed may be used, the liquid in tank 14 being Withdrawn forsuccessive treatments. For most purposes, however, it is preferred topass the drum with its rayon successively to a seriesof stations eachcomprising a unit similar to that described above. Such an arrangementis shown in Figs. 5 and 6.

As here indicated a drum 1a is mounted in the manner just described,between opposed heads supported in a frame 20 adjacent a spinningapparatus indicated generally by the numeral 21. The drum is driven by amotor 22, which may be used also to operate the laying mechanism. The

- spinning and laying mechanism may assume any of the conventional formsknown in the art, and they require no further description.

Extending from the collecting drum is a downwardly inclined trackway 23which passes to a series of units similar to that of Fig. 4, and finallyto a drier 24. These units preferably correspond in number to the numberof treatments which the material is to receive. For example, in theproduction of viscose rayon the rayon may be treated successively withwater, sodium sulfide solution for desulfurizing, water, a sour orsulfuric acid wash, chlorine solution for bleaching, a second sour wash,water, and finally, a. soap solution. In the apparatus shown separateunits are provided for each of these treatments, these being designatedA to H respectively.

The units are driven in tandem by a pinion 25 and gear 26 mounted ontrunnions 9, each pinion being connected to the gear on the nextsue-feeding unit by a chain 27, and gear 26 on the last unit beingdriven through a chain 28 and reduction gearingactuated in a cylinder31, whereby the head I may be moved inwardly and outwardly aciording toneed. After sufiicient rayon has been wound upon drum la, head 11 isbacked ofl", thcreby'lowering the drum to tracks 23, 011 which it rollsby gravity to unit A, where it is washed with Water in the mannerdescribed hereinabove. After being Washed the drum is released, and itpasses to unit B in which the rayon is desulfurized. From thence itpasses successively to units C to H, receiving appropriate treatments ateach station. are obtained by rotating the drums slowly, for example 15R. P. M. has been found to be suitable.

As indicated in Fig. 4, the treating solutions used in units B, D, E, Fand H may be circulated continuously by means of pmnps 16 described inconnection with Fig. 4. Units A, C and G are supplied with water byconduits 32 connected to a water line 33, the water passing through thedrum being permitted to go to waste. In all cases the liquid level ispreferably maintained substantially constant during treatment by addingliquid to compensate for that which seeps through perforations 56.

In order conveniently to control movements of the drums in passing tosuccessive stations, means are provided for simultaneously releasing allof the drums at the respective -stations, and for mechanically stoppingthem at the succeeding unit. In its simplest form such means comprises apair of reciprocable levers 34 mounted one on each side of and above theapparatus shown in Figs. 5 and 6. These levers are provided at eachstation with bell cranks 35 pivotally mounted in supports 36 carried byframework 10, and the lower arm of each of the cranks is provided with astop member 37.

The most satisfactory results Levers 34 are connected at one end topistonaetuated mechanism, indicated enerally by the numeral 38, wherebyall the drums nuiyfbe released or stopped simultaneously.

ter treatment at the last station, the drum rolls on tracks 23 intodrier 24, which in the form shown comprises a housing provided at eachend with a heating element 38 of any suitable driven b a motor 40, whichforces air over steam colls, notshown, through funnel members 41 intothe interior of the drum, forcing it outwardly through the perforations.A damper exhaust control 42 draws oil the air with its containedmoisture. The sides of the drier through which the drum is received anddischarged are closed in any conventional manner during drying. Afterhaving been properly dried the drmn is discharged from the drier, andthe completely treated material is then fabricated as desired. Forexample, in the .case of rayon it may be passed to a twisting machine43, the rayon being su plied to the twisting mechanism directly rom thedrum.

Various advanta es of the method and apparatus provide b the inventionhave been ointed out, an others will be discerned by those skilled inthe art. Among these are the economies which result from the use oflarge drums ada )ted to receive the product from a bank 0 spinnerets, ascompared with the single reels of small capacity which havecharacterized the prior art. Handling of the material is greatly reducedalso. So uniform and thorough action is obtained that the times oftreatment may be reduced from those which have been considered standardpractice. And concomitantly there is substantial reduction in the amountof liquid needed. For example 7 pounds of rayon wound upon a drmnembodying the invention may be washed satisfactorily with 150 gallons ofwnler,-wl\u'l\ represents a very significant savingcommercially over thepresent practice. smce particularly pure water isreqmred.

According tothe provisions of the patent statutes, we have explained theprinciple and mode of operation of our invent on and have described whatwe now consider to represent its best embodiment. However, we desire tohave it understood that, within the scope of the appended claims, theinvention may be practiced otherw se than as specifically illustratedand described.

We claim:

1. A process of treating rayon and the like precipitated fibers,comprising winding the material upon a drum the outer surface of whichis provided with a plurality of cuplike depressions having centrally oftheir bases perforations of small diameter, partly filling the drum withtreating liquid, and rotating the drum while permitting said type, forexample a fan 39- liquor to pass through said perforations uniler thepressure due to its gravity head on y.

2. A process of treating rayon and the like precipitated fibers,comprising winding the material upon a drum provided in its body portionwith a plurality of substantially uniformly spaced small perforationsthe outer ends of which terminate in the bases of cup-like depressionsin the drmn surface, partly filling said drum with a treating liquid andpermitting said liquid to ooze through said perforations under thepressure due to its gravity head only, and simultaneously rotatingthedrum in the direction in which the material was wound upon it.

3. A process of treating rayon and the like precipated fibers with aplurality of different liquids, comprising winding the materlal upon ahollow drum having in its bodysurfaces a plurality of opposedconcavltles connected by perforations of small hameter, supporting thedrum at a treat mg station, partly filling the drum with a treatlngliquid and permitting it to flow thrpugh the perforations and treat thematerial under its gravity head alone, and simultaneously rotating thedrum in the direction in which the material was wound u pon it, and whentreatment at said stat on is complete moving the drum successively todifferent stations and repeating such treatment with different liquids.

In testimony whereof, we hereunto sign our names.

\VILLIAM F. RICHTER. HAROLD E. MOCRERY.

